With gas metal arc welding, an inert gas is passed over the welding rod during the welding process so as to eliminate oxygen from the area of the weld. The presence of oxygen deteriorates the quality of the weld, and leads to imperfections in the welding. The presence of an inert gas, such as carbon dioxide or argon, eliminates the oxygen from the site and therefore enables proper welding. Gas metal arc welding is used with material such as, for example, stainless steel.
With present equipment, a welding head is used which has radially directed outlets in the diffusion body for the gas. This creates a turbulent flow within the nozzle and thus the gas exits the nozzle in a turbulent manner. This causes the gas to encapsulate some oxygen, which can lead to small, localised faults in the welding. It can also cause spluttering and inconsistent welding performance.
The significant problem with a turbulent flow is that it makes the gas very susceptible to being deviated from its intended path by external factors such as winds, breezes, or other forms of air flow. Therefore, in many instances, large shields are placed around the welding site in an attempt to eliminate, or at least reduce, unwanted air flows to thus enable welding to continue. However, this cannot be readily achieved in many situations such as, for example, large factories, or welding in the open. Therefore, there is significant loss of gas, loss of efficiency, and loss of productive work time. This has increased the cost of such welding, and reduced the reliability of such welding, to a significant extent.
It is therefore the principle object of the present invention to provide welding equipment, particularly for use in gas metal arc welding, whereby the gas flow is more controlled and is therefore less susceptible to deviation from its intended path by air flow.
A further object of the present invention is to provide welding equipment, particularly for use with gas metal arc welding, where the gas flow is more even and less turbulent and therefore has a reduced tendency to entrap air.